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FXAK67 PAJK 292325
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
325 PM AKDT Sun Jun 29 2025

.SHORT TERM...

Through tonight, there will finally be the downward trend of
precipitation in the northern half of the panhandle. With the
incoming developing system on Monday, dry, northerly air aloft will
sap away most of the available moisture. Haines and Skagway have the
highest chances of seeing some clearing late tonight. This may
extend down Lynn Canal down to the Juneau area, but there is only
around 30% chance to see some clearing.

While there is certainly some uncertainty on the overall track of
the Monday system, whether the surface low will stick around off the
coast of Sitka or move inland before dissipating, the results of
either solution are more clear. The warm front of precipitation will
move up the panhandle late Sunday night into Monday, bringing
moderate to heavy rain to the southern panhandle up to around
Petersburg. A shortwave moving along the upper level low looks to
bring some enhanced lift from both divergence ahead of the shortwave
and vorticity advection along the trough. This combined with
impressive warm air advection around 850 mb will prompt enhanced
lift from around 4 am to 10 am Monday. The upper level trough looks
to move up to around northern Lynn Canal by the afternoon hours, but
shearing effects from the mountains in the inner channels will keep
the low level advection minimal and localized to the southern half
of the panhandle. Therefore, in the southern panhandle, in
particular, around Ketchikan, Metlakatla, and southern PoW, expect
rates around 0.15 to 0.20 in/hr. Not expecting any flooding from
this event, due to the progressive nature of the heaviest rainfall,
limiting any impacts. That being said, some reduced visibility from
heavy rain is perfectly possible.

There is still a dry air intrusion around 700-500mb expected behind
the warm front, which previously lead to the thought of some gusty
winds following up the rain. Fortunately, it does look like CAA is
largely detached from the dry air, which will limit lapse rates for
any significant CAPE. Therefore, no longer expecting any gusty winds
behind the front, due to the lack of any significant forcing
mechanisms.

.LONG TERM...

Continued colder than normal temperatures, widespread overcast cloud
cover, and precipitation look to continue for the panhandle
through Tuesday, though more breaks in the cloud deck and less
rain could be in store for the latter half of the week, including
the Fourth of July. A cold upper level low will remain stationary
through July 3rd, before being ejected E into British Columbia,
only to be swiftly replaced by another cold upper level low moving
in from the W. While there is fairly solid confidence in the
larger synoptic scale pattern over the state during this timeframe
as a result, the same cannot be said for smaller scale details. In
particular, the various upper level troughs moving around the
first 500 mb low, have much less confidence on timing, strength,
and placement, as does the potential for a weak ridge in the lower
levels to try and build in during the latter half of the week.
What is known into next week is chances for rain will broadly
remain in the forecast, though the potential for fewer showers
July 3rd through the end of the week will exist.

Highest confidence is in the Monday/Tuesday system. A low will
stall and decay into an open trough off the coast of the AK
through the day on Tuesday before the remnants meander into the
panhandle and disintegrate entirely on Wednesday. During this
time, expect wave of showers to rotate around the decaying low,
moving into the panhandle and delivering rounds of rainfall to
much of the area. By Tuesday night, shower coverage will be
diminishing as the remnant trough continues to weaken.

Beyond Tuesday, confidence rapidly diminishes, but what can be
said is that cloud cover will linger and chances of rain showers
will continue, albeit diminished from what was previously
anticipated. Operational guidance indicates the potential for an
easterly wave moving across the northern half of the panhandle on
Wednesday. Alongside the easterly wave, chances for showers will
linger through the latter half of the week, but in the lull
between the former upper level low (which will be ejected
Wednesday), and the arrival of the next upper level low,
confidence has begun to grow that weak low level ridging will
attempt to build in. Should this ridging be sufficiently strong,
shower coverage will diminish across the area, and some
occasional breaks (and marginally warmer weather) are possible
Wednesday through the end of the week.

&&

.AVIATION...Rain showers persist but conditions have improved to
VFR or MVFR for most areas this afternoon. There are even some
clear breaks showing up on satellite imagery across the central
inner channels this afternoon. Lowest conditions are mostly in the
southern panhandle though with some ceilings down to 1300 ft. Some
gusty surface winds are still present in the Lynn Canal and
Skagway areas this afternoon, but winds elsewhere have calmed down
as well. Into tonight and tomorrow, the southern panhandle is
going to diverge from the northern panhandle conditions wise with
the south likely worsening (MVFR with possible IFR for both
ceiling and vis) as a new shortwave moves in bringing rain and a
little wind by late tonight. There might be some light turbulence
and maybe some low level wind shear in that area at times in the
morning as well. Meanwhile the north will likely see improving
conditions (up to VFR) as more easterly flow take over. Some areas
may also see some light sea breeze circulations Monday afternoon
in the north as well.

&&

.MARINE...

Outside: A developing low pressure will move along the coastline
of Prince of Wales island and decay next to Baranof Island Sunday
night into Monday. Early Monday morning will see a large shift to
northerly winds in the outer waters, with moderate to fresh
breezes out of Cross Sound and south of Baranof Island. As the low
moves to the west of Baranof Island, expect conditions to quickly
decay as the surface low becomes vertically stacked with the upper
level low. Given the short fetch, lack of stronger winds for
longer duration, and insignificant swell, not expecting a large
increase of significant sea heights at this time. Currently
expecting relatively constant wave heights around 4-5 ft.


Inside: As the developing low moves up, similar to the outer
coast, north south facing inner channels will flip to northerly,
and increase to a moderate to fresh breeze. In contrast for
Clarence Strait, moderate to fresh breezes look to continue from
the south to southeast through tomorrow evening and beyond. Expect
a shift between north to south moving up the panhandle from Monday
morning through Monday evening.

&&

.HYDROLOGY...Showers have mainly shifted to the east and began to
diminish. Satellite imagery does show training showers over the
Jordan Creek basin, with CMORPH2 rain rates indicating around 0.1
in/hr. While Jordan Creek may cross over into action, it is not
expected to reach minor flood stage at this time. Otherwise,
Montana Creek is not expected to raise significantly higher than
at time of writing.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

$$

SHORT TERM...NC
LONG TERM....GFS
AVIATION...EAL
MARINE...NC
HYDROLOGY...GFS

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